GIGABYTE GA-EX58-EXTREME problem with stability

Hi,

I have problem with work on my computer. To be honest I use this machine occasionally(in last two years) but last time need it very. I have issue with some strange behaviour(computer hangs, change memmory frequecy, have problem with boot/start), base on my configuration and post on few forums seems that some of persons had similar issues, but I dind't find post with same settings and solution.

Here is my setup:
Procesor Intel Core i7 920 2.66 GHz
GIGABYTE GA-EX58-EXTREME
OCZ DDR3 Triple Channel 3x2048MB 1600MHz CL9.0(OCZ3OB1600LV6GK PC3 12800 9-9-9@1.65v)
OCZ Modxstream Pro 600W Modular

First I made Bios update to F13s with hope that it help. With sets which are in attachment:

(I was try find some more or less similar configuration on forums with BIOS sets), yesterday I ran memtest86+ and all was good(no memmory error), after that run Prime95 25.11 to be sure and run, and also ok. So I thought that it is good settings. I start installation of Windows 7 Ultimate SP1 64bit but every time this process was hungs... so I gave up with hope that problem with installation CD or CD/DVD recorder.
Unfortunately today morning when try start computer is stop on bios post window. When finally start(after few restart/power off/on) I had message: "The system has experienced boot failures because of overclocking or changes in voltage." and memmory frequency back to 1066MHz. I check and with memmory frequecy 1066MHz or 1333MHz memtest86+ always reports error. Only on 1600MHz memtest86+ returns good results. My computer is still not stable.

I don't have good knowlege to change parameters in Bios so big ask for help/advise how to set it.

Many thx for help, Greg